Rotor Performance of a Full-Scale Heated Tail Rotor

A CFD approach using the NASA OVERFLOW code to predict the impact of ice accretion on a Bell 206 tail rotor is evaluated. The basis for the computational study is a test, conducted at the NASA Glenn Icing Research Wind Tunnel. The test acquired thrust and power measurements before, during, and after various ice accretion and blade heating cycles and also acquired ice shape geometric data from three-dimensional laser scans. For the CFD study, the measured ice shapes were utilized to develop computational grids and generate predicted results for thrust and power at various stages of ice accretion. It is shown that the computed results for the degraded performance are significantly different than the measurements. The lack of surface roughness modeling in the calculation is suspected to be a key contributor in the discrepancy.